A look at the 12 acts nominated for this year's £20,000 Mercury Prize, which will be announced on 1 November.

Alt-J - An Awesome Wave

Highest chart position: 19

Alt-J spent five years crafting their debut An Awesome Wave after meeting at Leeds University in 2007.

As singer Joe Newman said, the band "didn't want to look like morons, so we spent ages on the little things".

Now residing in Cambridge, they named themselves Alt-J after the command used on a Mac keyboard to create Greek letter Delta, which looks like a triangle and is also used to show change in mathematical equations.

The album made the Top 20 thanks to word of mouth more than any big marketing push, and it became one of the favourites to win the Mercury Prize before even being nominated.

Reviewers have found the genre-spanning album, dubbed "folk-step" by some, hard to categorise. The BBC called it "a deeply exciting, original and inventive debut".

Field Music - Plumb

Hailing from Sunderland, art rockers Field Music were formed in 2004 by brothers David and Peter Brewis.

Plumb is the band's fourth studio album and marks their first Mercury nomination.

The record has been noted for its "off-kilter song structures, a rhythm section reminiscent of the kitchen drawer being emptied at the top of the stairs, and frequent homage paid to the protagonists of new wave".

The band is often mentioned in the same breath as their north-eastern contemporaries Maximo Park and The Futureheads - for whom Peter once played drums.

Lianne La Havas - Is Your Love Big Enough?

Londoner Lianne La Havas was inspired to start singing after watching Lauren Hill in Sister Act 2 and is nominated for her debut Is Your Love Big Enough?

Having spent time as a backing singer for Paloma Faith, she was tipped for success by the BBC's Sound Of 2012 longlist before releasing this summer's retro-tinged soul record.

Rolling Stone called her "a natural who uses her six-string acoustic and her husky R&B croon to create songs that fall winningly between categories: Part Bill Withers-esque neo-soul, part Bon Iver-style indie folk."

The bubbly 23-year old has already supported Bon Iver on tour and likes to take pictures of the crowd to post on her blog.

Roller Trio - Roller Trio

Highest chart position: N/A

Described by the Guardian as "the latest group of technically awesome young genre-bending firebrands", Leeds band Roller Trio have already won praise from the likes of former Radio 1 DJ Gilles Peterson, who branded them "the new sound of UK jazz".

Comprising James Mainwaring (saxophone), Luke Wynter (guitar) and Luke Reddin-Williams (drums), the band describe their sound as "a visceral stew of conventional and experimental sounds", with influences as diverse as Tim Berne and Queens of the Stone Age.

The BBC praised for their debut album for its "taut lines that have a staccato if not stuttering quality, yet unleash a sizeable energy rush through volleys of needling four-, six- and three-note phrases".

The trio were recognised with a prestigious Peter Whittingham jazz award last year.